This is the first black hole photo in human history. Xinhua News Agency ( Event Vision Telescope Project Team Photo provided by)
Xinhua News Agency Shanghai April 10 Question: Exposure spanning 55 million light years: It turns out you are such a black hole!
Xinhua News Agency reporters Chen Fang, Dong Ruifeng, Wang Linlin
On April 10, 2019, humans finally saw the true appearance of the black hole!
, a "big film" released simultaneously in many places around the world, confirms the existence of mysterious celestial black holes, and also makes Einstein's century-old conjecture finally test!
After more than 10 years of preparation, eight observation points on four continents form a virtual telescope network - an event horizon telescope that is the size of the earth's diameter. After collecting all observation data and deeply analyzing it, the black hole finally has a "frontal photo".
Why do you want to take pictures of black holes? How difficult is it to get this photo? What new mysteries will humans reveal when they collaborate on exploring the universe? Xinhua News Agency reporters immediately interviewed Chinese and foreign scientists participating in international cooperation and gave answers to this.
"sees" black holes for the first time: Einstein said it right
In the vast starry sky, black holes are extremely mysterious and confusing celestial bodies.
It "devours" everything, and even the light cannot escape. It has a small size and a large mass, which can bend the surrounding space and time. Its "past and present" has many mysteries, which makes people extremely curious.
For more than a hundred years, humans have never stopped exploring the mystery of black holes.
From Einstein's general theory of relativity first predicted the existence of black holes, to Wheeler's concept of "black holes", to Hawking 's proposal that "black holes are distorted by time and space"... Scientists are increasingly convinced that there are many black holes of different sizes in the universe, and even a super-large black hole is in the center of the Milky Way.
Over the years, some indirect evidence has successively confirmed the existence of black holes, and humans have been constantly using science fiction wings to outline the appearance of black holes.
science fiction movies are also constantly "fantasizing" black hole images. In the movie "Interstellar", the black hole "Kagantuya" is the bottomless black center and a bright three-dimensional gas circle.
Just four years ago, the gravitational wave signal generated by the merger of two black holes was "captured" by scientists, becoming a milestone in the scientific community, and humans began to "hear" black holes.
This time, humans finally saw it.
The black hole that revealed its true appearance this time is located in the center of M87, a giant elliptical galaxy in Virgo, 55 million light years away from the earth, and its mass is about 6.5 billion times that of the sun. There is a shadow in its core area, surrounded by a crescent halo!
"The observation results are very consistent with theoretical predictions, which confirms that under extreme conditions such as black holes, general relativity is still valid." Shen Zhiqiang, director of the Shanghai Observatory of the Chinese Academy of Sciences, said that the theoretical model built by advanced scientists for our world has once again stood the test.
Researcher Lu Rusen at the Shanghai Observatory could not hide his excitement: "The shadow area and halo of a black hole are equivalent to opening a window. In the future, it can better reconstruct the physical process of black holes' 'swallowing' and gain an in-depth understanding of the strange events that occurred in this process."
What is the difficulty in taking photos? The difficulty of finding the "darkest signal"
in taking photos of black holes with unimaginable plans. In the eyes of experts participating in this big scientific plan, three words can be described in: "small", "dark" and "disturbance" - the details are too small, the signal is too dark, and there are too many interferences.
black hole is so far away, looking for it is like observing an orange on the moon from the earth, the telescope caliber required to be beyond imagination. Moreover, this telescope must be sensitive enough to "see" extremely tiny details clearly.
Since Galileo invented the telescope more than 400 years ago, the rapid improvement of human science and technology has made the telescope's caliber and the "division of labor" become increasingly thin.But to take pictures of black holes, relying on any single astronomical telescope available to humans is far from enough.
This is an unimaginable scientific plan: use 8 observation points distributed around the world to form a virtual telescope with a diameter of like the size of the earth. Observation points with harsh conditions include volcanoes in Hawaii and Mexico, Sierra Nevada in Spain, Atacama Desert in Chile and the Antarctic Pole, etc.
To take photos smoothly, you must not only "see" far, but also choose the right channel. "For black hole imaging, it is crucial to observe the best band. This band is around 1 mm, and the imaging resolution is equivalent to being able to read a newspaper on the Nansha Islands in Mohe, Heilongjiang," said Lu Rusen.
Different telescopes have their own strengths. It is this special requirement for taking pictures of black holes that has made some large telescopes, including " China Sky Eye ", "stand by and watch".
Experts explain that the black hole electromagnetic wave radiation in this band is brightest, while the background "noise" interference is minimal.
is difficult to take photos and is not easy to take photos. The massive amount of data recorded by the telescope requires complex post-processing and analysis to obtain the final black hole image.
Take the observation in April 2017 as an example. The data rate of each station reached an astonishing 32GB/sec. The 8 stations recorded a total of about 3500TB of data during the 5-day observation period. Experts say that if you watch it continuously like watching a movie, it will take at least 500 years to finish it.
The head of the international cooperation project and professor at Harvard University said that over the past 10 years, it was the technological breakthrough and the completion of a new telescope that ultimately enabled humans to "see" black holes.
has become the first-class, and China has become an important participant in international scientific cooperation
From the first photo of the moon back to the first photo of the black hole, a new window for humans to observe the universe is constantly opening. In the journey of exploring the mysteries of the universe, China is also constantly contributing its wisdom.
Chinese scientists participated in the international cooperation on taking photos of black holes throughout the process, and made contributions to the early promotion of this international cooperation, telescope observation time application, Hawaii telescope observation operation, post-data processing and theoretical analysis.
Shen Zhiqiang said that international cooperation in basic scientific research is the general trend, but in many cases, we cannot rely solely on funding to "make up the crowd". Early research and talent accumulation are important factors in obtaining the "discourse power" for cooperation.
From "China Sky Eye" (FAST) to "World Eye" (SKA), from human genome sequencing to pan-third pole environmental research, in recent years, China's participation in international cooperation has continued to increase in breadth and depth, while absorbing world innovation nutrients, it has also continuously contributed Chinese wisdom.
As global radio astronomy is in full swing, four major astronomical discoveries have emerged one after another. In recent years, my country has successively built a number of radio telescopes, with a diameter ranging from 25 meters to 65 meters to 500 meters. From catching up to running side by side, astronomy research has gradually become the first-class.
"In the past 100 to 20 years, China has made tremendous progress in the fields of radio astrophysics, astronomy, etc., and has made an indispensable contribution to this international cooperation." Heino Falke, a professor at the University of Nijmegen in the Netherlands, said that with the rapid growth of China's radio interference measurement and space exploration capabilities, China will become an important participant in international scientific cooperation. The smooth imaging of the
black hole is not the end point.
Anton Census, director of the Max Planck Institute of Radio Astronomy, who chaired the European regional press conference, emphasized that the number of telescopes will be increased in the future, and even observe new black holes will be observed, and the relevant predictions of general relativity will be continued to verify the formation and evolution of galaxies and solve more mysteries for mankind...
Einstein said that science is endless, it is an eternal mystery.
"With the support of the great dream, the pace of human scientific exploration will never stop." Shen Zhiqiang said.(Participated reporters: Liu Fang, Zhang Yirong, Lian Zhen, Huang Kun, Jin Liwang)
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-